2026-09-21T07:45:25Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/73107 2023-07-11 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

Tawfick, Sameh Chen, Ping-Ju 2015-01-21T19:59:34Z 2015-01-21T19:59:34Z 2017-01-22T10:15:40Z 2014-12 2015-01-21 2014-12 State-of-the art microfabrication techniques enable new understanding of surface phenomena such as liquid wetting and dry adhesion. This understanding led to a surge of design and fabrication of novel non- and directional wetting, self-cleaning, anti-biofouling and energy efficient surface textures. This work focuses on designing new dynamic surfaces that can change their micro and nanoscale texture due to in-plane mechanical strain. The studied textured surfaces have vertical 1D nanostructures, such as carbon nanotubes, integrated on flexible carrier films with inclined angle-tunable microstructures. An example of hierarchical geometry is proposed and fabricated using a double-molding technique. Finite Element Analysis shows that the nanostructure angle can be tuned from –45 to +40 degrees while the space among their periodicity changes by 320% due to in-plane tensile film strain. Two types of molds are designed and fabricated: inclined wavy surface features fabricated with stereolithography with periodicity of 250 microns and kinematically coupled alignment grooves; tilted SU8 microstructures with periodicity of 50 microns made by inclined photolithography. Both molds were used to cast films of 100 micron thickness from polydimethyl siloxane (PDMS); and releasing the film was achieved using a sacrificial mold coating of 300 nm thick PMMA. With PDMS thin films bearing arrays of nanostructures with tunable angles, these surfaces can change surface roughness by external stimuli; for instance, by applied mechanical strain, further change a wide range of optical, wetting, adhesive and other surface properties. In other words, the strategy here is not only with reversible surface properties but also can be triggered by a wide range of stimuli. Item withdrawn by Laura Spradlin (lspradl2@illinois.edu) on 2014-12-12T13:57:39Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Chen_Pingju.docx: 11059236 bytes, checksum: 608e0e497ffac5d84538d6472a9ed1db (MD5) Chen_Pingju.pdf: 2591510 bytes, checksum: f05e6d841188abf299b7f6a2c6f3a635 (MD5) Made available in DSpace on 2015-01-21T19:59:34Z (GMT). No. of bitstreams: 5 Ping-Ju_Chen.pdf: 2576343 bytes, checksum: 5e4075f8360e290357fd332a8643b41e (MD5) Chen_Pingju.docx: 11059668 bytes, checksum: 6adc0728d2e31ed42ed43e12829c31d0 (MD5) 0_Chen_Pingju.docx: 11059668 bytes, checksum: 6adc0728d2e31ed42ed43e12829c31d0 (MD5) 1_0_Chen_Pingju.docx: 11059668 bytes, checksum: 6adc0728d2e31ed42ed43e12829c31d0 (MD5) 1_Chen_Pingju.docx: 11059668 bytes, checksum: 6adc0728d2e31ed42ed43e12829c31d0 (MD5) Embargo set by: Seth Robbins for item 73296 Lift date: 2017-01-21T19:59:39Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Limited Restriction Lifted for Item 73296 on 2017-01-22T10:15:40Z. http://hdl.handle.net/2142/73107 en Copyright 2014 Pingju Chen Dynamic Surfaces Anisotropy Asymmetry wavy surfaces polydimethyl siloxane (PDMS) wetting Design and manufacturing of PDMS micro structures with dynamic inclination angle text Mechanical Sci & Engineering 1917 Mechanical Engineering 0133 University of Illinois at Urbana-Champaign Thesis M.S. MS:Mechanical Engineerng -UIUC 10KS0133MS